Reuters 22 Jul 09;
SYDNEY (Reuters) - An El Nino continues to develop in the Pacific Ocean with sea temperatures above average, but other weather indicators are fluctuating, Australia's weather bureau said on Wednesday in its latest report.
"While El Nino indicators have fluctuated over the past few weeks, the overall picture remains one of a developing El Nino event," the Bureau of Meteorology said.
"Ocean conditions in the Pacific Basin remain at El Nino levels. Should they persist at such levels through the remainder of the southern winter and into spring, as predicted by the world's leading climate models, 2009 will be considered an El Nino year."
El Nino, meaning "little boy" in Spanish, is driven by an abnormal warming of the eastern Pacific Ocean and creates havoc in weather patterns across the Asia-Pacific region.
It is associated with drought conditions in parts of Australia and Asia and wetter-than-normal weather in parts of South America.
India this year suffered its worst start to the vital monsoon rains in eight decades, causing drought in some states.
The last severe El Nino in 1998 killed over 2,000 people and caused billions of dollars worth of damage to crops, mines and infrastructure in Australia and Asia.
The Australian weather bureau said Pacific Ocean temperatures remained at about 1 degree Celsius above average and that cloud patterns and rainfall along the equator were now becoming consistent with a developing El Nino event.
However a major indicator of an El Nino, the Southern Oscillation Index (SOI), was running contrary to a normal El Nino development.
The SOI, which measures the pressure difference between the Pacific island of Tahiti and the Australian city of Darwin, was currently at a positive 12, while a consistently negative SOI indicates an El Nino.
The bureau said the positive SOI was due to a high pressure system near Tahiti and warmer than expected sea temperatures in the western Pacific and Coral Sea.
For more information: www.bom.gov.au/climate/enso/
(Reporting by Michael Perry; Editing by Clarence Fernandez)
